sjmisc (version 1.3)

to_na: Convert missing values of labelled variables into NA

Description

This function converts defined missing values that are stored as original value code into NA.

Usage

to_na(x)

Arguments

x

variable (vector), data.frame or list of variables with value label attributes and defined missing value codes (see labelled).

Value

• x, where each value code of missing values is converted to NA.

Details

to_na converts values to NA, which are defined as missing through the is_na-attribute of a vector (see labelled). set_na, by contrast, converts those values to NA that are specified in the function's values argument; hence, set_na ignores the is_na-attribute. Furthermore, see 'Details' in get_values and get_na.

See Also

get_na to get value codes of missing values.

Examples

# create labelled factor, with missing flag
x <- labelled(c("M", "M", "F", "X", "N/A"),
              c(Male = "M", Female = "F",
                Refused = "X", "Not applicable" = "N/A"),
              c(FALSE, FALSE, TRUE, TRUE))
x
get_na(x)
to_na(x)

# create labelled integer, with missing flag
x <- labelled(c(1, 2, 1, 3, 4, 1),
             c(Male = 1, Female = 2, Refused = 3, "N/A" = 4),
             c(FALSE, FALSE, TRUE, TRUE))
x
get_na(x)
to_na(x)

# get summary
x <- labelled(c(1, 2, 1, 3, 4, 1, NA, 5),
              c(Male = 1, Female = 2, Refused = 5),
              c(FALSE, FALSE, TRUE))
frq(x)